Cord fabric and method of impregnating the same



W. COVERLY Oct. 27, 1936.

CORD FABRIC AND METHOD IMPREGNATING THE SAME Filed Aug. 23, 1930 2 Sheets-Sheet l INVENTOR 'IEIIIIIIIIIII ATTORN EYS Oct. 27, 1936. COVERLY 2,058,954

CORD FABRIC AND METHOD OF IMPREGNATING THE SAME Filed Aug. 25, 1950 2 Sheets-Sheet 2 INVENTOR 20/750? CBDef/ ATTORNEYS Patented Oct. 27, 1936 UNITED STATES PATENT OFFICE CORD FABRIC AND METHOD OF IMPREGNATING THE SAME William Coverly, Sandwich, Ontario, Canada Application August 23, 1930, Serial No. 477,331

Claims. (01. 117-2) gether to form the strands are not reached by the impregnating fluid. This'is an indication that the impregnation has not fully accomplished f its intended object.

The object of the present invention is' to enable more thorough impregnation and is accomplished essentially by applyingthe impregnating fluidbefore the cord is completed. 1

The conventional cord fabric consists of cords laid in juxtaposition. Each cord consists of a number of strands twisted together, and each strand in turn consists of a number of threads twisted together. According to the invention, the impregnating fluid is applied to the threads while in their separated condition and before they are twisted into strands. The resulting impregnation is quite thorough and complete inasmuch as 0 it is performed while the material is in the finest state of subdivision in which it can practically be treated. A fabric which has been impregnated in this manner is superior in tensile strength, flexibility, adhesive qualities and the absenceof internal friction than a fabric impregnated by prior methods.

The invention is fully disclosed by way of ex ample in the following description and in the accompanying drawings, in which-- Figure 1 is a vertical longitudinal section of an apparatus for performing the process of the invention; i

Fig. 2 is a section on the line 2-2 of Figure 1; and

Fig. 3 is a perspective view illustrating the man.-

ner of forming the cord.

Reference to these views will now be made by use of like characters which are employed to designate corresponding parts throughout.

The apparatus for making and impregnating the cord includes a suitable housing i forming a chamber in which the impregnation takes place. Several twisting devices are supported in the lateral walls of the housing i, and inasmuch as all 55 of these devices are alike, a description of one of them will suflice. These devices are, moreover, conventionally illustrated and include each a shaft 2 carrying a head or plate 3. The member 3 in turn carries a plurality of draw plates 6, each m of which supports a. desired number of spools A cross- (not shown) or other means for delivering threads. The shaft 2 is driven by bevel pinions 5, and internal gearing may be provided for rotating the members 4 on their respective axes. Each member 4 is adapted to deliver a plurality of threads 6 which are twisted into a strand 1 by turning of the member 4. Suitable means, presently to be described, is provided for drawing the material from the plates 4 and maintaining it in the position shown in Figure 1. The motion of the head 3 in turn twists the strands 1 into a cord 8.

The cords formed by opposed twisting devices are brought together between central rollers 9 which are preferably corrugated or grooved in 15 order to pull the cords away from the forming devices. These devices are successively offset from each other in the lateral direction, so that the cords lie in juxtaposition in traveling through the rollers, whereby to form a fabric of ordinary appearance.

Spray tubes it are positioned in the housing I directly above or adjacent the threads 6 in their separated condition, so that the material issuing from the sprayers impregnates the threads while 25 in their separated condition and before being wound into strands or cords.

The impregnation of the threads in their separated condition constitutes the important feature of this invention and results in more thorough 30 impregnation than has hitherto been obtained by existing methods. The material delivered by the members l0 may be rubber or rubber compound or in fact any material suitable for impregnation according to the use to be made of the ultimate 35 product.

At the top of the housing I are mounted conduits it connected as at l2 to the chamber and adapted to supply hot dry air thereto in order to reduce the moisture content of the impregnating 4o material after it has been applied to'the threads. The bottom of the housing slopes as at I3 downwardly to a drain M for carrying off the impregnating material which reaches the bottom. The bottom is also connected to suction exhaust pipes it for carrying off the fumes of the rubber solution and for maintaining a proper circulation of hot air. The system is controlled in such a manner that the juxtaposed cords pass through the outlet H5 at the bottom'of the chamber in a tacky condition permitting them to stick together.

As will be seen, the twisting of the threads into strands and the strands into the cord takes place during the period when the material being twisted is under continuous suspension conditions, the only support for the material being provided-by the thread carriers 4 at one end of the zone of suspensionand by the rollers 9 which support and draw the cords at the other an end of the zone. The impregnatingmaterial is applied during the movement of the threads en route to the twisting bite for the strand.

As a result, the threads travel as'individuals for a short distance during which period absorption of the impregnating material into the thread material can take place naturally. As the threads approach the bite-the point where the actual twisting of the thread material into the strand form takes placethey pass into mutual contact relation which is carried to the completely twisted condition in which the usual pressure conditions are present. Hence, the mutual action tends to set up a squeezing effect in that the threads and impregnating material carried thereby are subjected to the pressure set up by the twisting action to not only provide for maximum impregnation of the threads but also to place the excess as a coating for the strand produced. These strands then pass to the twisting bite for the cord, where the operation repeats the pressure characteristics, etc., the pressure being active not only on the coating of the strands but on the threads of the strands, thus causing the coating material to be additionally squeezed to ensure proper impregnation internally of the cord and also placing the excess as a coating on the cord. Throughout this period during which the initial material hasbeen subjected to the successive twisting and bite-pressure activities, the activi ties have been provided within the continuous suspension zone of the travel path of the material, with the travel path through the zone in a generally-horizontal direction. Hence, the actual development of the cord from the initial threads takes place without the opportunity of removing impregnating material from the traveling development excepting such as might be provided by the pressure developments of the two bites, and then only in directions laterally of the travel path; the effect of the bite development will tend to distribute the impregnating material rather than to remove it from the developing cord.

This action takes place in presence of the heated air circulation, so that as the progression takes place, the tendency is for the impregnating material to lose its moisture during the progression, but, as above pointed out, the drying characteristic does'not provide complete drying action, since the cords still have the tacky characteristic when they pass through the outlet i6, as pointed out above. In other words, there is a progressive loss of moisture of the applied material, but the loss is more or less controlled by the fact that only the surface coating is actually subjected to it through direct contact with the air, so that the tacky condition remains after the threads have been developed ino the cord structures. As indicated, the tacky condition is such as to cause adjacent cords to adhere together to provide an embryo fabric characteristic.

In this arrangement, therefore, assurance is had that the cord content is thoroughly impregnated, not only in connection with thread impregnation but, additionally, the voids present within the strands and wit? in the cord also contain the material since the squeezing action during the twisting tends to force all excess into any voids that may be present.

A cord impregnated in the manner described has been found to have greater tensile strength,

more flexibility and greater adhesive qualities than fabric impregnated by previous methods. A cross section of a fabric impregnated by prior methods shows that certain of the threads within the strands fail to receive the impregnating liquid. Inasmuch as internal friction within a fabric is in inverse proportion to the completeness of impregnation, a fabric impregnated according to this invention possesses far better wearing qualities in an automobile tire than a fabric impregnated by other methods. In this connection it may be said that one of the principal causes of tire wear and blow-outs is the heating due to internal friction.

Although a specific embodiment of the invention has been illustrated and described it will be understood that various alterations in the details of construction may be made without departing from the scope of the invention as indicated by the appended claims.

What I claim is:-

l. In the production of impregnated cord formations, the method of developing the formation which consists in successively twisting the threads into strands and the developed strands into the cord formation with both twisting activities provided during travel of the material -under a continuous and uninterrupted suspension condition 'and applying the impregnating material to the threads within the suspension zone and while en route to the bite of the strand being twisted to thereby subject the impregnated threads to pressure produced within the twisting bite of the strand and to subject the resultant product to pressure produced within the twisting bite of the cord.

2. A method as in claim 1 characterized in that the impregnating material is in the form of a flowable material of rubber-like characteristic.

3. In the production of impregnated cord formations, the method of developing the formation which consists in successively twisting the threads into strands and the developed strands into the cord formation during travel of the material under continuous suspension, and in the presence of heated air in circulation, and applying the impregnating material to the threads within the suspension zone and while en route to the bite of the strand being twisted to thereby subject the impregnated threads to pressure of the twisting bite of the strand and to subject the resultant product to pressure of the twisting bite of the cord- 4. In the production of impregnated cord formations, the method of developing the formation which consists in successively twisting the threads into strands and the developed strands into the cord formation with both twisting activities provided during travel of the material under a continuous and uninterrupted suspension, and spraying the impregnating material on to the threads within the suspension zone and while en routeto the twisting bite of the strand, whereby the successive twisting activities will be developed upon the threads in direct succession to the threadspraying activity within the suspension zone of the travel path of the material.

5. A method as in claim 4 characterized in that the impregnation and successive twisting activities are made manifest in the presence of heated air in circulation.

WILLIAM COVERLY. 

